Electromagnetic solenoids are used in a variety of applications, including all-wheel drive clutches. One known type of electromagnetic solenoid is disclosed in U.S. Pat. No. 7,785,224. These known types of electromagnetic solenoids include an armature and a cup-shaped ring including an annular coil housed therein. A distance between the armature and the cup-shaped ring is controlled by the energization state of the annular coil. In known electromagnetic solenoids for clutches, the armature and cup-shaped ring typically include flat axially extending pole ends facing each other. FIGS. 1 and 2 show an electromagnetic solenoid 1 according to the prior art. As shown in FIGS. 1 and 2, the electromagnetic solenoid 1 includes a cup-shaped ring 5 and a ring-shaped armature 7, each including flat pole ends facing one another. In this embodiment, the flat pole ends on the cup-shaped ring and armature provide a higher attractive force when the armature and cup-shaped ring are closer to each other, i.e. at a smaller stroke distance. As the distance between the armature and cup-shaped ring increases, i.e. at a larger stroke distance, the attractive force between the armature and cup-shaped ring due to the energized annular coil precipitously decreases. It would be desirable to provide an electromagnetic solenoid assembly including mating pole end faces that maintain a more constant attractive force between the armature and cup-shaped ring as the distance between the armature and cup-shaped ring increases and the stroke increases.